diff options
| author | Ian Buckley <ian.buckley@gmail.com> | 2010-10-20 15:45:44 -0700 |
|---|---|---|
| committer | Matt Ettus <matt@ettus.com> | 2010-11-11 12:10:35 -0800 |
| commit | aa9643f60e91d00cd7990acde44efad17c2509ed (patch) | |
| tree | 20214c4b511485d8d68326d5a55ef2a54f24a556 | |
| parent | 7e75951d263c00e9f84bdf14d6176680cb3de833 (diff) | |
| download | uhd-aa9643f60e91d00cd7990acde44efad17c2509ed.tar.gz uhd-aa9643f60e91d00cd7990acde44efad17c2509ed.tar.bz2 uhd-aa9643f60e91d00cd7990acde44efad17c2509ed.zip | |
Placed 2nd DCM into `ifdef DCM_FOR_RAMCLK which is dissabled by default
Derived RAMCLK from 270degree offset of principle core DCM giving
theoretical 2.5nS timing advance on RAM_CLK relative to RAM_* signals.
| -rwxr-xr-x | usrp2/top/u2plus/u2plus.ucf | 8 | ||||
| -rw-r--r-- | usrp2/top/u2plus/u2plus.v | 22 |
2 files changed, 23 insertions, 7 deletions
diff --git a/usrp2/top/u2plus/u2plus.ucf b/usrp2/top/u2plus/u2plus.ucf index 3717b3d91..54dfd2a33 100755 --- a/usrp2/top/u2plus/u2plus.ucf +++ b/usrp2/top/u2plus/u2plus.ucf @@ -415,10 +415,10 @@ TIMESPEC "TS_ser_rx_clk" = PERIOD "ser_rx_clk" 10 ns HIGH 50 %; TIMESPEC "TS_clk_div_to_dsp_clk" = FROM "clk_div" TO "dcm_out" 10 ns; -NET "CLK_FPGA_P" CLOCK_DEDICATED_ROUTE = FALSE; -PIN "DCM_INST/DCM_SP.CLKIN" CLOCK_DEDICATED_ROUTE = FALSE; +#NET "CLK_FPGA_P" CLOCK_DEDICATED_ROUTE = FALSE; +#PIN "DCM_INST/DCM_SP.CLKIN" CLOCK_DEDICATED_ROUTE = FALSE; -NET "RAM_CLK" CLOCK_DEDICATED_ROUTE = FALSE; -PIN "DCM_INST1/DCM_SP.CLKFB" CLOCK_DEDICATED_ROUTE = FALSE; +#NET "RAM_CLK" CLOCK_DEDICATED_ROUTE = FALSE; +#PIN "DCM_INST1/DCM_SP.CLKFB" CLOCK_DEDICATED_ROUTE = FALSE; diff --git a/usrp2/top/u2plus/u2plus.v b/usrp2/top/u2plus/u2plus.v index 55b5bd8f4..5396ae6cd 100644 --- a/usrp2/top/u2plus/u2plus.v +++ b/usrp2/top/u2plus/u2plus.v @@ -1,4 +1,5 @@ `timescale 1ns / 1ps +//`define DCM_FOR_RAMCLK ////////////////////////////////////////////////////////////////////////////////// module u2plus @@ -195,7 +196,7 @@ module u2plus .CLK2X180(), .CLK90(), .CLK180(), - .CLK270(), + .CLK270(clk270_100), .LOCKED(LOCKED_OUT), .PSDONE(), .STATUS()); @@ -216,7 +217,8 @@ module u2plus BUFG dspclk_BUFG (.I(dcm_out), .O(dsp_clk)); BUFG wbclk_BUFG (.I(clk_div), .O(wb_clk)); - + +`ifdef DCM_FOR_RAMCLK wire RAM_CLK_buf; wire clk100_ext; wire clk100_ext_buf; @@ -258,7 +260,21 @@ module u2plus .D1(1'b0), .R(1'b0), .S(1'b0)); - + +`else // !`ifdef DCM_FOR_RAMCLK + // assign RAM_CLK = dcm_out; + BUFG clk270_100_buf_i1 (.I(clk270_100), + .O(clk270_100_buf)); + OFDDRRSE RAM_CLK_i1 (.Q(RAM_CLK), + .C0(clk270_100_buf), + .C1(~clk270_100_buf), + .CE(1'b1), + .D0(1'b1), + .D1(1'b0), + .R(1'b0), + .S(1'b0)); +`endif + // I2C -- Don't use external transistors for open drain, the FPGA implements this IOBUF scl_pin(.O(scl_pad_i), .IO(SCL), .I(scl_pad_o), .T(scl_pad_oen_o)); IOBUF sda_pin(.O(sda_pad_i), .IO(SDA), .I(sda_pad_o), .T(sda_pad_oen_o)); |